import java.util.Scanner;

/**
 * DP34 【模板】前缀和
 * https://www.nowcoder.com/practice/acead2f4c28c401889915da98ecdc6bf?tpId=230&tqId=2021480&ru=/exam/oj&qru=/ta/dynamic-programming/question-ranking&sourceUrl=%2Fexam%2Foj%3Fpage%3D1%26tab%3D%25E7%25AE%2597%25E6%25B3%2595%25E7%25AF%2587%26topicId%3D196
 */
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        //1、输入数据
        int n = in.nextInt();
        int q = in.nextInt();
        int[] arr = new int[n + 1];
        //把数据写进数组
        for(int i = 1; i <= n; i++) {
            arr[i] = in.nextInt();
        }
        //2、预处理一个前缀和数组
        long[] dp = new long[n + 1];//防止溢出
        for(int i = 1; i <= n; i++) {
            dp[i] = dp[i - 1] + arr[i];
        }
        //3、使用前缀和数组
        while(q > 0) {
            int l = in.nextInt(), r = in.nextInt();
            System.out.println(dp[r] - dp[l - 1]);
            q--;
        }
    }
}